This invention relates generally to the art of ophthalmic surgery devices and procedures relating to "repair" of a damaged natural iris. The word "repair" herein is employed to refer both to iris-replacement and iris-augmentation. More particularly, it pertains to a novel artificial iris device, and to a unique surgical method for installing and positioning that device in a subject's eye to replace all or a part of a damaged iris. The term "subject" is used herein principally to refer to a human subject, but those skilled in the art will recognize that the new features of this invention are relevant also to animals.
Several forms of devices made in accordance with the present invention, and several surgical approaches employed to utilize these devices, are described and illustrated herein, with focus given particularly to the installation of such a device either within the ciliary sulcus in a selected eye, or immediately in front of an artificial lens and within the capsular bag in an eye.
In general terms, the artificial iris device of the present invention takes the form of a relatively thin (typically in the range of about 0.1- to about 0.3-millimeters), flexible, bio-compatible web or expanse of a suitable material, such as a silicone material, formed generally with a body-of-revolution annular flat, generally washer-like configuration having inner and outer diameters selected, as will be explained, to "match" certain natural dimensional characteristics of a selected eye wherein the device is to be employed. The body of the proposed device has a generally radially extending slit (radially, that is, relative to the central, axis of revolution of the device) which extends completely from the inside diameter to the outside diameter at one location in the device, thus to give the device a split-ring-like quality. Typically, the nominal outside diameter will be sized so that, depending upon where the device is to be positioned in an eye, it is about the same as, or just slightly less than, either (1) the outside (internal) diameter of the ciliary sulcus, or (2)--therefor the outside diameter of the interior of the inside perimeter of the capsular bag. This dimension, generally, is somewhere the vicinity of about 10-millimeters, give or take whatever is necessary to fit the device into its intended ultimate placement location. The nominal inside diameter of the device, which inside diameter defines a nominal artificial pupil opening, is typically in the range of about 3- to about 4-millimeters.
The radially inner and radially outer edges in the device are preferably smooth and substantially circular, and the expanse, or main body, in the device is preferably either light-opaque or slightly light-transmissive (particularly in the region adjacent the device's inner edge). Further, the body in the device preferably is suitably colored (by any appropriate conventional technique) so that it will substantially match the color appearance of the natural iris with respect to which it is to be employed. This color may either be a selected uniform color or, probably more preferably, a variegated color, which variegation generally mimics that which is seen in the pupils of natural eyes.
In its intended ultimate environment, the iris device of this invention acts as a singularity, in the sense that no other device needs to be installed with it in order for it to perform its intended function. The device uniquely lends itself to very simple and very manageable insertion-into-place by the fact that it permits smoothly flowing threading of itself into an eye, generally along what can be thought of as its circular long axis, with such threading progressing from one of the "ends" that are defined in the device by the slit mentioned above. Such threading, according to the invention, takes place through an extremely small surgical incision prepared near the perimeter of the cornea. Insertion of the device is performed with little distortion of the natural tissues in the eye because of the fact that it can be threaded or snaked rotationally through such an incision, as distinguished from being bunched, gathered, folded, etc. and forced through an incision opening.
As the detailed description which now follows below is read in conjunction with the accompanying drawings, other features and advantages of the proposed device will become more fully apparent, as will also the unique installation surgical methodology which it permits.